Ustekinumab isn't on the market. Its maker, Centocor Inc., had asked the FDA to consider approving ustekinumab to treat chronic moderate to severe plaque psoriasis in adults. The FDA wants more information before making a decision, according to a news release Centocor issued in December 2008.

In The Lancet, researchers including Alice Gottlieb, MD, of Tufts Medical center in Boston report that ustekinumab trumped a placebo at treating psoriatic arthritis in adults studied for 36 weeks.

"Ustekinumab significantly reduced signs and symptoms of psoriatic arthritis and diminished skin lesions compared with placebo, and the drug was well tolerated," Gottlieb and colleagues write.

"Adverse events and infections were similar in each treatment group and serious adverse events arose only with the placebo," the study states. But the researchers caution that larger, longer studies are needed to further study ustekinumuab for the treatment of psoriatic arthritis.

Centocor funded the study, and several of Gottlieb's colleagues are Centocor employees.

Ustekinumab looks like "an attractive option in psoriatic arthritis," states an editorial published with the study. But "we should, nevertheless, remain vigilant for potential complications," write the editorialists, who included Raquel Cuchacovich, MD, of the rheumatology section of the Louisiana State University Health Sciences Center in New Orleans.